Multiple-break enclosed-type circuit interrupters with external rotary contact driving means and single chamber construction



Nov. 25. 1969 R. E. VOSHALL 3,480,750

MULTIPLE-BREAK ENCLOSED-TYPE CIRCUIT INTERRUPTERS WITH EXTERNAL ROTARY CONTACT DRIVING MEANS AND SINGLE CHAMBER CONSTRUCTION Filed Oct. 19, 1966 2 Sheets-Sheet .L

INVENTOR Roy E. VoshcH ATTOR NEY NOV. 25. 1969 VOSHALL 3,480,750

MULTIPLE-BREAK ENCLOSED-TYPE CIRCUIT INTERRUPTERS WITH EXTERNAL ROTARY CONTACT DRIVING MEANS AND SINGLE CHAMBER CONSTRUCTION 2 Sheets-Sheet 2 Filed Oct. 19, 1966 United States Patent MULTIPLE-BREAK ENCLOSED-TYPE CIRCUIT IN- TERRUPTERS WITH EXTERNAL ROTARY CON- TACT DRIVING MEANS AND SINGLE CHAMBER CONSTRUCTION Roy E. Voshall, Mount Lebanon, Pittsburgh, Pa, assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 19, 1966, Ser. No. 587,869 Int. Cl. H01h 9/30 US. Cl. 200-144 9 Claims ABSTRACT OF THE DISCLOSURE A multiple-break enclosed-type of circuit breaker is provided, utilizing a single-envelope construction, and a rotary-type external driving means, which is connected through a sealing device, or devices, interiorly of the single envelope to effect rotary opening and closing motion of the interiorly-situated contact structure. In one form a single sealing device is provided about a lateral arm and a central opening of the envelope is used accommodating a rotary external driving shaft. Internal connecting and supporting structure may be used to simultaneously operate the multiple-break contact structure.

In other forms of the invention, provision is made for purely axial motion of the movable contact shafts, which extend through sealing devices.

In still other forms of the invention, the single-envelope structure is of annular configuration with the external rotary driving shaft extending through a central opening of the annularly-shaped envelope structure. An enclosed highly-effective arc-extinguishing gas, such as sulfurhexafluoride (SP gas, may be the enclosed gas to facilitate arc extinction, or the single envelope may be evacuated, as in a vacuum-type circuit interrupter.

This invention relates, generally, to enclosed-type circuit interrupters and, more particularly, to multiple-break enclosed-type circuit interrupters utilizing a simplified operating contact means and a single envelope construction.

A general object of the present invention is to provide an improved enclosed-type circuit interrupter having a single enclosed interrupting chamber with improved means for effecting contact motion from the region externally of the interrupting chamber.

Another object of the invention is to provide an improved multiple-break enclosed-type circuit interrupter in which the number of actuating bellows may be reduced with a consequent simplification of contact motion.

Another object of the invention is to provide an improved enclosed-type circuit interrupter in which multiple breaks are utilized for interrupting either high-voltage or high current circuits, and a simplified-type of driving means is employed to effect contact motion.

The present invention is particularly concerned with a multiple-break circuit interrupter, preferably of the vacuum-type, which utilizes a single enclosure. Singlebreak vacuum-type circuit interrupters seem to be limited to a voltage class of 14.4 kv. or less. A multiple-break vacuum interrupter has the advantage that when the contacts are in the open position, the withstand voltage per set of contacts is less than that for a single-break interrupter. This makes the current-interrupting ability of the vacuum-type circuit breaker less severe. During an alternatingcurrent circuit interruption, the arc is established between the two parted contacts. After the alternating current approaches a current zero, the arc is extinguished, and the restored voltage appears across the open contacts. The rate of rise of this voltage is determined by the type of fault and circuit parameters. An electrical breakdown may occur across the separated contacts, if the rate of rise of the restored voltage is too high. This may cause arcing to occur for an extra one-half cycle of current. With multiple sets of contacts in series, the restored voltage divides across the multiple sets of contacts. Therefore, the rate of rise of the restored voltage across each set of separable contacts is reduced making a breakdown less probable.

Accordingly, it is a further object of the present invention to provide an improved vacuum-type circuit interrupter in which multiple-break contacts are utilized, and a simplified-type of rotary externally-situated mechanism is utilized in conjunction with a flexible wall portion of the enclosed vacuum interrupting chamber.

According to one aspect of the present invention, an enclosed interrupting chamber housing at least two sets of separable contacts are utilized with a rotary member situated externally of said chamber, and transmitting motion to the movable contact structure interiorly of the interrupting chamber through a flexible wall portion of the interrupting chamber. In one form of the invention, there is provided a generally cylindrically-shaped interrupting chamber with a rotary shaft extending through the central opening of the cylinder, and having laterallyextending contact support arms, which extend through interior sidewall openings of the interrupting chamber through bellows structures to effect interior opening and closing contact movement without a loss of vacuum.

Another form of the invention uses a rotary member transmitting contact motion interiorly of the enclosed interupting chamber through a single bellows, and still a third form of the invention uses quadruple contacts all simultaneously actuated by a rotary member rotating externally of the interrupting envelope.

Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings, in which:

FIGURE 1 is a plan sectional view of one form of the invention, the contact structure being illustrated in the closed-circuit position, and the view being taken along the line II of FIG. 2;

FIG. 2 is a vertical sectional view taken substantially along the line IIII of FIG. 1;

FIG. 3 is a diagrammatic view showing how the two contact structures may be employed in electrical parallel for increased current-carrying ability;

FIG. 4 illustrates a modified-type of construction in which the bellows flexing occurs in a generally longitudinal direction;

FIG. 5 illustrates another modified-type of construction in which only a single bellows is utilized;

FIG. 6 illustrates a quadruple-break circuit interrupter using a single bellows and an externally-situated driving shaft, the contact structure being illustrated in the closedcircuit position; and

FIG. 7 illustrates a modified-type of vacuum circuit interrupter in which a pure axial motion of the contact bellows is insured with no side motion of the bellows being permitted, thus reducing the stress thereon.

Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally designates a vacuum-type circuit interrupter including a generally cylindrically-shaped evacuated envelope 2, within which are disposed two pairs of separable contacts 5, 6 and 7, 8. The set of separable contacts 5, 6 includes a stationary contact 6 and a movable contact 5 carried by a movable operating arm 10, which extends through a flexible bellows 12 to a central region 14 at atmospheric pressure. As viewed in FIG. 1, it will be noted that a rotary driving shaft 16 is provided having laterally-extending therefrom, the contact operating arm 10. It will, therefore, be obvious that rotary clockwise opening motion of the rotatable driving shaft 16 will effect opening separating motion of the movable contact from the stationary contact 6 to provide one break within the evacuated envelope 2.

Similarly, the rotary driving shaft 16 has laterallyextending therefrom, in a generally diametrically-opposite direction, a second contact operating arm 18, which carries the movable contact 7, which is separable from the stationary contact 8 of the serially-related pair of separable contacts 7, 8. As shown in FIG. 1, the stationary contacts 6, 8 extend externally of the evacuated envelope 2 through terminal studs 20, 21 to line connections L L The electrical circuit passes through the vacuum-type circuit interrupter 1 in an obvious fashion, namely through the line-terminal stud 20, stationary contact 6, movable contact 5, conducting contact arm 10, conducting rotary shaft 16, conducting operating arm 18, movable contact 7, stationary contact 8, and terminal stud 21 to the other line connection L of the controlled circuit.

As mentioned, clockwise opening rotary movement of the driving shaft 16 will simultaneously effect two breaks within the generally cylindrically-shaped enclosed interrupting chamber or evacuated envelope 2.

To prevent the deposition of metallic vapor upon the insulating outer cylindrical casing 23, there is provided a pair of semi-circular members 25, 26 constituting condensing shields, which may be formed of any suitable metallic material, such as copper, nickel, aluminum, or the like. Additionally, the upper and lower end walls 28, 29 (FIG. 2), which may be of metal, may support end condensing shields 30, 31, which assist the condensing shields 25, 26 in preventing vapor from being deposited upon the insulating outer casing wall 23.

To protect the two bellows 12 from having metallic vapor deposited thereon, there is preferably provided generally cup-shaped condensing shields 32. The inner tubular wall 34 of the evacuated envelope 2 may be of metallic material to facilitate attachment of the outer ends of the bellows 12, the voltage being withstood by the outer insulating casing 23.

With the foregoing arrangement, it will be apparent that clockwise opening movement of the rotary shaft 16, as viewed in FIG. 1, effects simultaneous contact opening interiorly of the evacuated envelope 2, whereas counterclockwise closing movement of the rotary shaft 16 will simultaneously effect contact closing.

FIG. 3 diagrammatically illustrates how the two sets of contacts 3, 4 may be utilized in electrical parallel to increase the current-carrying capacity of the modifiedtype circuit interrupter 35. It will be noted that the line connection L may be made directly to the rotary shaft 16, and the stationary contact supports 20, 21 may be electrically connected together by circuit connections 38, 39 to the other line terminal L It will be obvious from the construction set forth in FIG. 3 that each pair of contacts 5, 6 and 7, 8 will carry substantially one-half the line current, and they will cooperate together to increase the current-breaking capacity of the device 35. Since both movable contacts 5, 7 are simultaneously actuated, the arc-extinguishing action occurs simultaneously with each set of contacts 5, 6 and 7, 8.

FIG. 4 illustrates a modified-type of construction 43 in which the flexing imposed upon the bellows 12 occurs in a generally axial direction by the use of contact operating arms 45, 46, which, when driven by the shaft 16, impose generally longitudinal flexing action upon the bellows 12. The other component parts of the modifiedtype of interrupter 43, illustrated in FIG. 4, are identical to those set forth in FIG. 1; consequently, a further description thereof appears unnecessary.

In the modified-type of construction 48 illustrated in FIG. 5 of the drawings, it will be noted that there is utilized only a single bellows 12, which transmits rotary movement of the driving shaft 16 to the movable contacts 5, 7. Since a single bellows 12 is utilized, instead of two or more, there is a simplified construction provided, with the expense minimized.

FIG. 6 illustrates a quadruplebreak vacuum-type circuit interrupter 52 in which only a single bellows 12 is employed, and supporting structure 54, disposed interiorly of the evacuated envelope 2, provides the desired current-conducting relationships. The metallic portions of the rotary supporting structure 54 is indicated by the reference numerals 55-59, whereas the insulating portion is indicated by the reference numeral 60. With the modified-type of construction 52 illustrated in FIG. 6, it will be noted that rotary opening and closing movement of the drive shaft 16 effects, through the single bellows 12, simultaneous opening and closing movement of the several sets of contacts 62-69. The stationary contacts 65, 67 are supported from two conducting post supports 70, 71 welded or brazed to a conducting portion 2a of casing 2. The stationary contacts 62, 69 are preferably supported directly by conducting terminal leads extending through terminal bushings 76, 77.

As illustrated in FIG. 6, the electrical current path through the interrupting device 52 comprises line connection L terminal stud 74, extending through bushing 77, to stationary contact 62. The electrical circuit then extends from the movable contact 63 through a conducting portion 55, 56 of the rotary supporting structure 54, to the movable contact 64. Then the electrical circuit extends from the stationary contact 65 through the conducting walls 2a of envelope 2 to stationary contact 67. In similar fashion, the movable contact 66 is connected by a conducting portion 58, 59 with the movable contact 68 of the set of separable contacts 68, 69. The circuit then extends through the terminal stud 73 to the line connection L It will be obvious that with the construction set forth in FIG. 6 that clockwise opening rotary motion of the driving shaft 16 will effect, through the support arm 80, clockwise opening motion of the interiorly-situated supporting structure 54 to simultaneously effect opening motion of the four series sets of separable contacts. In similar fashion, counterclockwise closing rotary motion of the driving shaft 16 will effect simultaneous contact closing through the device 52.

In the modified-type interrupting device 81 illustrated in FIG. 7 of the drawings, purely linear or axial motion of the contact operating rods 82, 83 is assured by stationary guides 84, 85 and pinand-slot connections 86, 87. This reduces side motion stress upon the sealing bellows 12 and prolongs their life.

Although the invention has been described in connection with a vacuum-type circuit interrupter, nevertheless certain features thereof may be applicable to an interrupting device utilizing a highly-effective arc-extinguishing gas, such as sulfur-hexafluoride (SP gas. In other words, instead of the region interiorly of the envelope 2 being evacuated, it may be filled with a highly-efficient arc-extinguishing gas under pressure, and prevented from leaking to the atmosphere by the use of the bellows 12.

Although metallic flexible bellows 12 have been indicated throughout the several devices, nevertheless it will be obvious to those skilled in the art that in place of metallic bellows, rubber diaphragms, metallic diaphragms, or other equivalent sealing devices having flexibility may be employed.

Although there has been illustrated and described specific "structures, it is to be clearly understood that the same were merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

I claim as my invention:

1. A vacuum-type circuit interrupter including a round evacuated envelope having a central opening therethrough at atmospheric pressure, a rotary drive shaft extending through said central opening, at least one lateral contact operating arm carried by said rotary drive shaft and extending outwardly within said round evacuated envelope through a sealing device, two or more separable pairs of contacts disposed within the evacuated envelope and secured to the inner extremity of said arm for rotary opening and closing movement.

2. The combination of claim 1, wherein two lateral contact operating arms are employed, each having a sealing device associated therewith, and at least one movable contact secured to the inner extremity of each lateral contact operating arm for simultaneous contact separation within the round evacuated envelope.

3. The combination of claim 1, wherein the end annular casing plates (28), (29) are metallic.

4. A multiple-break vacuum-type circuit interrupter, comprising in combination:

(a) means defining a round evacuated envelope having a central opening (34) therethrough at atmospheric pressure;

(b) a rotary drive shaft extending through said central opening;

(c) at least one rotary crank-arm linkage means (10, 18, 45, 80, 82, 83) carried by said rotary drive shaft and having a portion thereof extending within the round evacuated envelope hermetically sealed thereto;

(d) a pair of stationary contacts disposed within the round evacuated envelope; and

(e) a movable contact fixedly secured to the outer extremity of said crank-arm linkage means and cooperable with one of the stationary contacts to establish an are within the evacuated envelope.

5. The multiple-break vacuum-type circuit interrupter of claim 4, wherein the rotary drive shaft has two such rotary crank-arm linkage means for effecting the simultaneous opening and closing of two such movable contacts.

'6. The multiple-break vacuum-type circuit interrupter of claim 4, wherein purely lineal motion of movable contact rods is provided by at least one stationary guide 40 7. The multiple-break vacuum-type circuit interrupter of claim 4, wherein the outer wall of the round evacuated envelope is of insulating material and a pair of semicircular condensing shields (25, 26) cooperate to prevent metallic deposition occurring on the inner surfaces of the outer insulating wall of the envelope.

8. An enclosed type circuit interrupter including a round enclosed envelope having a central opening therethrough at atmospheric pressure, a highly effective arcextinguishing gas disposed Within said enclosed envelope and contained therein, a rotary drive shaft extending through said central opening, at least one lateral contact operating arm carried by said rotary drive shaft and extending outwardly within said round enclosed envelope through a sealing device, two or more separable pairs of contacts disposed within the enclosed envelope and secured to the inner extremity of said arm for rotary opening and closing movement.

9. The combination of claim 8, wherein two lateral contact operating arms are employed, each having a sealing device associated therewith and at least one movable contact secured to the inner extremity of each lateral contact operating arm for simultaneous contact separation within the round enclosed envelope.

References Cited UNITED STATES PATENTS 2,140,475 12/ 1938 Hilliard. 2,144,414 1/1939 Milliken. 3,236,978 '2/1966 Lester.

FOREIGN PATENTS 5 1 6,6 5 2 1/1931 Germany. 561,915 10/1932 Germany. 264,433 1/ 195 0 Switzerland.

ROBERT S. MACON, Primary Examiner US. Cl. X.R. 200-448 

